Process and contrivance for superheating steam taken from a generator.



'WITNFSSESZ G. OAILLE. PROGBSS AND GONTBIVANOB FOR SUPBRHEATING STEAM TAKEN FROM A GENERATOR.

APPLIOATION FILED r33. 7, 1912.

1,063,953. Patented June 10,1913.

3 SHEETSBHEET 1.

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0. .GAILLE. moms AND OONTRIVANGE FOR SUPBRHEATING STEAM TAKEN FROM A GENERATOR.

APPLIOATION FILED I'IIB. 7, 1912.

1,063,953 Patented June' 10, 1913.

2 SHEETS-SHEET 2.

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CHARLES CAILLE, OF LEPIERRYEUX, FRANCE I ROCESS AND CONTRIVANCE FOR SUPERHEA'IING STEAM TAKEN FROM A GENERATOR.

Specification of Letters Patent.

"utented June 10,191 3.

Application filed February '7, 1912. Serial No. 676,045.

, To all whom it may concern:

Be it known that 1, CHARLES Gamma, a citizen of the Republic of France, residing at 24 Rue de la Graite, Leperreux, Seine, France, have invented new and useful linproveinents in Processes and Oont-rivances for Superheating Steam Taken from a Generator, of which the following is a specification.

Hitherto, when for supplying engines with steam,.it is desired to obtain the steam as dry as possible, the steam, during its passage from the steam. generator to the cylinders or other consumption devices, is caused to traverse a group of tubes (a su 'icrheater) exposed to hot gases. By these previous methods and contrivances, steam which is always in theeondition of saturated steam can only be dispossessed of its moisture by an increase of temperature, so that super heaters as at present constructed must be of considerable size, and'in addition it is neces sary to locate them at a portion of the passage which conducts the hot gases not far from the furnace. Moreover, when a superheater of this kind is insutliciently supplied with fliiid to be superheated on account of a diminution or cessation more or less prolonged in the employment of steam, there is a risk of the group of tubes being burned unless complicated con'trivances to prevent this are rovided. The process and contrivance tor super-heating steam taken from a generator, which process and eontrivance form the subject of the present invention, eliminate all these disadvantages.

The new process consists, in principle, in producing by means of an expansion device, located in the passage traversed by the steam in passing from the outlet valve to the superheater, an expansion which preferably is constant, that is, which produces a reduction in pressure'which is practically constant, the space into which the fluid expands being maintained at the temperature of the constriwtion of a contri'vance for applying this principle to a locomotive is illustrated as a representative example in the annexed drawing, in which:

Figure l is a part: longitudimtl section of a lotmmotive boiler to which the invention is assumed to he applied. Fig. 2 is a sectional elevation oil? the detail of a special expansion device which permits of a constant degree ol. expansion of the steam in its passage from the outlet valve to the superheater.

In Fig. 1, (t represents the shell of a locomotive boiler provided with a steam dome Z! in which is located the usual steam outlet valve 0. The steam from the boiler is led to a. pipe a which opens into an expansion chamber c. On leaving the said chamber 6, the steam is nmintaincd at the same temperature as that previous to its expansion and for this purpose flows through a collector 'l' which may he a single tube of suitable dimensions or a group of tubes located. in the steam space g of the shell (I. of the generator. From the collector the steam passes to the superhcuter 71, which may be smaller than usual and be located in the smoke box '1' of the locomotive. The ell'cct caused by the (expansion of the steam during its passage from the pipe (I to the super heater [1. with n'iainl'cnunce 01? its initial tempm'aturc is easily understood. ()wing to the expansion at constant temperature, the water in suspension in the Sltjttlll taken from the steam dome vaporized; the collector f thus forms a chamber of total vaporization, so that the steam reaches the superheater h in the condition ol gas. in the superlumter 1. it undergoes an increase in temperature, which accompaniml by an increase oi pres sure which is maintaimd until the steam is admitted to the cylinders oi the engine. At each admission of steam to the engine cylinders a reduction of pressure takes place in the collector f. The expansion device 0 then allows .lrcsh steam to pass into the col- I but such that the difference between the variable pressure P in the steam space and the variable pressure p .in the collector f, shall be a constant, the magnitude of which can be chosen and regulated at will. In other words the contrivance should be so constructed that if P represents the variable ressure in the boiler, 72 the variable pressure 111 the collector f, Pp:7c at any moment, 70 10 being a constant chosen at will and regulated by the tension of the spring or the weights with which the expansion device 6 is loaded. In addition, the temperature of the expanded fluid is maintained at the tem-' perature of the fluid to be expanded in such a manner thatat each expansion there is a corresponding vaporization of the water in the steam, that is to say, a drying of the steam taken from the generator. The ex- '.pansion device which permits'this constant reduction in pressure to be obtained, and which is shown in Fig. 2, consists of: a casing e communicating on' the one hand, by

. means of an orifice 6 with the space g of the generator and on the other hand a branch 6 projecting from the said casing is connected to the pipe 03 on which is carried the steam-outlet valve 0 under the control of the driver. Within the casing e is fitted the expansion contrivanceitself which comprises a box-shaped chamber 9' which communlcates by a pipe 7' with the collector f. In this box is provided a cylindrical casing m having two series of apertures 01., n the opening and closing of which establishes and breaks respectively communication between 0? and f. This partial or total opening and closing is determined according to the position of the movable element of the expansion device.

This-element comprises for the two series of holes n, W two pistons, 0, 0 of the same diameter connected by a rod g. A passage e leading from the branch e is formed in the Wall of the casing c; orifices 1, 2, 3 place this passage e and consequently the branch 6 into communication respectively with the upper surface of the piston W, the lower surface of the piston T the upper surface of the piston T and also the lower surface of this last mentioned piston. In other words the.branch e is, by means of the passage 6 in constant communication with the chambers '0, 2, u. Thechamber y is on the other hand in communication by means of a passage 'w, formed in the wall of the casing c, with the chamber y' of the expansion device. The two pistons r and r are of the same diameter, the piston 1' being of greater diameter. These three pistons are carried by the rod (1, which is continued through the cover of the casing e and has at its upper end a head on which rests a spring a; the compression of which can be regulated. The compression of the said spring determines e5 precisely the constant is which is equal to P-p as defined above, and insures the expansion of the fluid which passes from the boiler through the steam valve 0. The steam admitted at d is conveyed through c and 6 respectively to the casing m and the spaces '0, t, it. But the pistons 1' and T have the same diameter, and the pressure of the fluid tobe expanded is the same on each; it is the same with the two pistons 0 and 0 On the other hand the piston r is on its lower surface subjected to the action of the fluid to be expanded, and on its upper surface it is exposed to the pressure which exists in the chamber 7'. If S be the area of the piston 7 s the area of the piston 1*, then the rod 9 and the pistons which it carries tend to move up under theaction of a force represented by (S-s)P, while the same elements are subjected to a counteracting force represented by (Ss)7) to which is added the compression 74 of the spring 00. The pistons 0, 0 accordingly take a position of equilibrium effecting a partial closure of the expansion device, which corresponds to the equation which may be written As Ss is constant it is only necessary to vary the value of la inorder to vary the value of P-p. When, during a working stroke, the Value of 72 diminishes during an admission stroke of the piston of .the engine, the value of P-p will increase and the equib librium will be destroyed, the orifices n and n being thereby uncovered. As described above, the steam expanded from a pressure P to a pressure p is maintained at a temperature the mimmum magnitude of which is equal to the temperature of the steam in the boiler, by placing the collector f in the steam space or at any other place of higher temperature. The drying of the steam, expanded by the means described above, thus takes place almost entirely in the collector, thus permitting the size of the superheater to be reduced to a minimum.

In connection with the special superheating device described above it should be noted 1 5 that the arrangement of the piston r of area S between the two pistons r and r of area 8 allows the value of theconstant 7a to be reduced, while leaving the values of S and s suiiiciently high for eflicient working. short, if the value of is be low, the expansion device will work with the necessary scnsitiveness and speed without the effects of inertia interfering with its eflicient operation.

Of course the collector f could in certain cases perform the dual function of collector and .supcrhoater or this dual function could be assigned to the superheater alone, the characteristic feature of the contrivance 13C described being always the isother mic ex ceive steam from the boiler and communieating with said collector, whereby said collector will receive the expanded steam, said collector being exposed to the steam from the boiler.

2. In combination, a boiler provided with a steam space, a steam collector and means adapted to receive steam from the steam space and deliver it into said collector, said means being responsive to the dilference in pressure between the steam in the steam space and the steam in the collector thereby maintaining constant the difierence between Losses.

the pressure in the steam space and the pressure in the collector.

3. In combination, a boiler, a collector a chamber communicating with said collector, said chamber having a port to permit steam from the boiler to enter said chamber, a valve cimlrollingr said port and means controlled by the dilt'emnce in pressure between he steam, in the llUllti and the steam in the collector in nominal the movement of Said valve.

In testimony whereof I have signed my name to this 1 two Sillmtt'iblhgy; witnesses.

Cl [ARLES GAIL-LE.

H. 0. Corn.

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